package com.yitiao.base;

public class StringFormat {
    public static void main(String[] args) {
//        Object obj = null;
//        System.out.println(StrUtil.format("{}?id",obj));
//        System.out.println("123".concat("123"));
        String str = new String("111");
        cont(str);
        System.out.println(str);
        Integer a=0;
        addnum(a);
        System.out.println(a);
    }

    private static void addnum(Integer a) {
        a+=4;
    }

    private static void cont(String str) {
        str+="22";
    }
}
